Evaluation of Fiberglass and Aluminum Ladder Stability During a Simulated Tethered Operator Fall Event

Abstract

Ladder-related falls are common in many industries and lead to high rates of injury and hospitalization. This study aimed to establish safety criteria for ladder stability and potential for failure in the event of an operator fall when equipped with a fall arrest system that has been attached to the ladder as opposed to a fixed structure anchor point. All combinations of five variables were tested in a custom-built load drop apparatus: ground surface, leaning surface, force direction, operator tether method, and ladder type. Overall, all conditions tested in this investigation with a simulated worker falling from a ladder with the fall arrest device attached to the ladder rails or a rung resulted in a pass. While there were clear deformations to the aluminum ladders and there were 3 failures due to repeated drop tests on the same ladder, replication of failed tests on a new ladder passed the failure conditions. Given a ladder that is in good working condition, has not be subjected to prior falls or damage, is properly erected and secured - a worker with a mass below 113kg (250lb) would be safely restrained when tethered to the ladder as opposed to the lanyard being tied off to a structure or a lifeline based on the simulated mass drops performed in this study in controlled laboratory conditions.